A method commonly used for producing (meth)acrylic esters is transesterification. It is known practice, for example according to documents GB 960 005, EP 298 867, EP 619 309 or EP 960 877, to prepare the (meth)acrylic esters of formula (I):

in which R is a hydrogen atom or a methyl group, and it being possible for R1 to be a linear or branched alkyl radical, or a cyclic aliphatic, aryl, alkylaryl or arylalkyl radical, which may contain heteroatoms, according to a method of transesterification by reacting an alkyl (meth)acrylate of formula (II):

in which R has the abovementioned meaning and it being possible for R2 to be a linear or branched alkyl group having from 1 to 4 carbon atoms,
with an alcohol of formula (III):R1—OH
in which R1 has the abovementioned meaning.
During the synthesis, light alcohol R2—OH is generated and is eliminated in the form of an azeotrope with the light alkyl (meth)acrylate (II).
The synthesis of (meth)acrylic esters by transesterification is generally carried out in the presence of a catalyst. The choice of the catalyst depends on various criteria, in particular on the nature of the alkyl (meth)acrylate (II) used, but also on the nature of the alcohol (III) used to prepare the (meth)acrylic ester. In addition to the criteria of efficiency and selectivity, other factors may be involved, such as commercial availability, cost or toxicity of the catalyst.
As examples of catalysts described in the literature for catalyzing the preparation of (meth)acrylic esters by transesterification, mention may in particular be made of:                Acid catalysts, such as methanesulfonic acid or para-toluenesulfonic acid: these catalysts have the drawback of being relatively nonselective and corrosive.        Basic catalysts, such as alkali metal salts or alkaline-earth metal salts: these catalysts are active but prove to be relatively nonselective.        Chelates of titanium, zirconium, iron, zinc or calcium with 1,3-dicarbonyl compounds, such as Ti, Zr, Fr, Zn or Ca acetylacetonates: these compounds are active and selective, but generate acetylacetone and are sensitive to the presence of 1,2- or 1,3-diols. In addition, they rapidly lose their activity and as a result are not recyclable.        Tin derivatives, such as dialkyl tin oxides, dialkyl tin dialkoxides and dialkyl tin diesters, in particular di-n-butyltin oxide (DBTO and homologs thereof), are generally active and selective. However, with these catalysts, there is the problem of their elimination in the distillation residues owing to the toxicity of tin.        Titanium alkoxides, such as tetraalkyl (ethyl, n-propyl, isopropyl, n-butyl, etc.) titanates, or alternatively dimethylaminoethyl titanate or titanium phenolate: they are catalysts that are generally active and selective, but sensitive to water.        Enzymes of which the use is described in patent JP 04 079889.        
Titanium alkoxides have been found to be active and selective catalysts and the use thereof is recommended in particular in methods for the synthesis of dialkylaminoalkyl (meth)acrylates.
Mention may be made of European patent EP 298 867, which describes in particular the preparation of N,N-dimethylaminoethyl acrylate (DMAEA) in the presence of tetraethyl titanate according to a method of transesterification by reacting ethyl acrylate with dimethylaminoethanol.
In patent EP 960 877, the dialkylaminoalkyl (meth)acrylates are obtained in the presence of a transesterification catalyst chosen from tetrabutyl, tetraethyl and tetra-(2-ethylhexyl) titanates, using methyl or ethyl (meth)acrylate with an amino alcohol. In order to obtain a product of high purity, it is, however, necessary to first carry out tailing, i.e. elimination of the catalyst and of the heavy products, followed by topping and a final rectification of the crude reaction mixture.
When it is a question of producing a dialkylaminoalkyl (meth)acrylate, such as DMAEA, by transesterification starting from methyl (meth)acrylate, it is difficult to envision using a titanium alkoxide such as tetraethyl titanate, because of the gradual appearance of a white precipitate which is completely insoluble in the reaction medium, which proves to be tetramethyl titanate. This is because, in the presence of the methanol generated during the transesterification, there is an exchange of ligands with the titanate used, and formation of methyl titanates, of which tetramethyl titanate, which is insoluble, is the ultimate end point. In addition to the phenomenon of deactivation of the catalyst and, consequently, slowing down of the reaction kinetics, clogging of the reactor and of the ancillary equipment thereof also occurs, which is unacceptable on the industrial scale.
In the article POLYMER, vol. 39, no. 24, (1998), pages 6109-6114, Deleuze H. et al., describe the transesterification of methyl acrylate with 2-ethyl-hexanol in the presence of a supported catalyst which is in the form of polymer beads onto which titanate functions are grafted, the advantage being that of being able to easily separate the catalyst from the reaction medium by filtration.
The article by N. Lewis et al., in SYNLETT, No. Spec. ISS, 1999, pages 957-959, describes the transesterification of methyl methacrylate with bromoundecanol in the presence of a catalyst constituted of a titanate grafted onto a polystyrene support, which can be readily separated from the reaction medium by simple filtration.